Washington (CNN) -- When China decided to test an anti-satellite missile in 2007, the impact shattered not just the target satellite but any illusions that China did not have military intentions in space and the capabilities to achieve them.

The United States is still ahead in space development, but China has been making impressive progress in expanding its own program -- and it has not gone unnoticed.

"I think anyone who's familiar with the space business, and particularly the history, our history in the space business over the years, would have to be absolutely amazed at the advancements that China has made in such a short period of time," said Gen. Kevin Chilton, head of the U.S. Strategic Command, which is in charge of the military's space operations.

"They certainly are on a fast track to improve their capabilities," Chilton said in early November. "They're to be commended for the achievements that they've done in such a short period of time."

China's intentions in space are a matter of great interest to the United States.

The Pentagon is trying to encourage more transparency by the communist country and last month hosted a delegation that included Gen. Xu Caihou of China's Central Military Commission. Xu met with Defense Secretary Robert Gates and toured various U.S. installations, including STRATCOM, which oversees space, cyberspace and nuclear military operations.

"Where they're heading, I think, is one of the things that a lot of people would like to understand better," Chilton said. He would not speak in detail about any of the discussions between U.S. and Chinese officials.

Any hope for transparency will be tough to come by. China itself may not have a handle on its intentions, said Roger Cliff, a Chinese military analyst at RAND, a global policy think tank. Cliff said there is an internal struggle within the Chinese military for who will control the space mission.

China's president has said its space efforts are "peaceful." But a top Chinese military official spoke of offensive and defensive capabilities in space because "only power could protect peace," Chinese air force Cmdr. Xu Quiliang told the Xinhua news agency.

"It is not clear, and in part the reason for that is because China isn't clear where it is going in space, because they are still arguing it out," Cliff said.